3PIQ | pdb_00003piq

Crystal structure of human 2909 Fab, a quaternary structure-specific antibody against HIV-1

External Resource: Annotation

Domain Annotation: ECOD Classification
Domain Annotation: CATH
IMGT Antibody Annotation
SAbDab Antibody Annotation

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
L [auth K]	Ig_2	e3piqK3	A: alpha bundles	X: Subtilisin-like	H: Subtilisin-like	T: Subtilisin-like	F: Ig_2	ECOD (develop294)
J [auth I]	Gal-bind_lectin	e3piqI1	A: alpha bundles	X: Lipocalins/Streptavidin	H: Zn-dependent exopeptidases	T: Zn-dependent exopeptidases	F: Gal-bind_lectin	ECOD (develop294)
H [auth F]	Ig_2	e3piqF3	A: alpha bundles	X: Subtilisin-like	H: Subtilisin-like	T: Subtilisin-like	F: Ig_2	ECOD (develop294)
F [auth D]	Gal-bind_lectin	e3piqD1	A: alpha bundles	X: Lipocalins/Streptavidin	H: Zn-dependent exopeptidases	T: Zn-dependent exopeptidases	F: Gal-bind_lectin	ECOD (develop294)
D [auth B]	Gal-bind_lectin	e3piqB1	A: alpha bundles	X: Lipocalins/Streptavidin	H: Zn-dependent exopeptidases	T: Zn-dependent exopeptidases	F: Gal-bind_lectin	ECOD (develop294)
B [auth L]	Gal-bind_lectin	e3piqL1	A: alpha bundles	X: Lipocalins/Streptavidin	H: Zn-dependent exopeptidases	T: Zn-dependent exopeptidases	F: Gal-bind_lectin	ECOD (develop294)
K [auth J]	Gal-bind_lectin	e3piqJ1	A: alpha bundles	X: Lipocalins/Streptavidin	H: Zn-dependent exopeptidases	T: Zn-dependent exopeptidases	F: Gal-bind_lectin	ECOD (develop294)
I [auth G]	Gal-bind_lectin	e3piqG1	A: alpha bundles	X: Lipocalins/Streptavidin	H: Zn-dependent exopeptidases	T: Zn-dependent exopeptidases	F: Gal-bind_lectin	ECOD (develop294)
G [auth E]	Gal-bind_lectin	e3piqE1	A: alpha bundles	X: Lipocalins/Streptavidin	H: Zn-dependent exopeptidases	T: Zn-dependent exopeptidases	F: Gal-bind_lectin	ECOD (develop294)
E [auth C]	Gal-bind_lectin	e3piqC1	A: alpha bundles	X: Lipocalins/Streptavidin	H: Zn-dependent exopeptidases	T: Zn-dependent exopeptidases	F: Gal-bind_lectin	ECOD (develop294)
C [auth A]	Gal-bind_lectin	e3piqA1	A: alpha bundles	X: Lipocalins/Streptavidin	H: Zn-dependent exopeptidases	T: Zn-dependent exopeptidases	F: Gal-bind_lectin	ECOD (develop294)
A [auth H]	Gal-bind_lectin	e3piqH1	A: alpha bundles	X: Lipocalins/Streptavidin	H: Zn-dependent exopeptidases	T: Zn-dependent exopeptidases	F: Gal-bind_lectin	ECOD (develop294)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
L [auth K]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
J [auth I]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
H [auth F]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
F [auth D]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
D [auth B]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
B [auth L]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
K [auth J]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
I [auth G]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
G [auth E]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
E [auth C]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
C [auth A]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
A [auth H]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)

IMGT Antibody Annotation IMGT Database Homepage

Chain	Protein Name	Description	Organism Name	Gene Allele Name(s)	Domain Name(s)	Receptor Type	Receptor Description	Provenance Source
B [auth L], D [auth B], F [auth D], H [auth F], J [auth I], B [auth L], D [auth B], F [auth D], H [auth F], J [auth I], L [auth K]	2909 mAb, anti-gp120 [HIV-1], neutralizing stain specific	L-LAMBDA	Homo sapiens (human)	IGLV3-2101, IGLJ701, IGLC201, IGLC202, IGLC3*04	V-DOMAIN V-LAMBDA, C-DOMAIN C-LAMBDA	IG	FAB-GAMMA-1_LAMBDA	IMGT (202610-0)
A [auth H], C [auth A], E [auth C], G [auth E], I [auth G], A [auth H], C [auth A], E [auth C], G [auth E], I [auth G], K [auth J]	2909 mAb, anti-gp120 [HIV-1], neutralizing stain specific	VH-CH1	Homo sapiens (human)	IGHV3-4301, IGHJ603, IGHG1*03	V-DOMAIN VH, C-DOMAIN CH1	IG	FAB-GAMMA-1_LAMBDA	IMGT (202610-0)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
B [auth L], D [auth B], F [auth D], H [auth F], J [auth I], B [auth L], D [auth B], F [auth D], H [auth F], J [auth I], L [auth K]	Light Chain	IGLV3	Lambda	-	SAbDab (2026-03-20)
A [auth H], C [auth A], E [auth C], G [auth E], I [auth G], A [auth H], C [auth A], E [auth C], G [auth E], I [auth G], K [auth J]	Heavy Chain	IGHV3	-	-	SAbDab (2026-03-20)

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM157729. RCSB PDB uses resources of the National Energy Research Scientific Computing Center (NERSC), a Department of Energy User Facility.